2000/10/13 by Alexander Wong, Nelson Christensen · 3 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.63.044301
published as Physical Review A, Vol. 63, 044301 (2001)
arxiv created 2000/10/13 · arxiv updated 2009/12/01
We discuss entanglement of multiparticle quantum systems. We propose a potential measure of a type of entanglement of pure states of n qubits, the n-tangle. For a system of two qubits the n-tangle is equal to the square of the concurrence, and for systems of three qubits it is equal to the ''residual entanglement''. We show that the n -tangle, is also equal to the generalization of concurrence squared for even n, and use this fact to prove that the n-tangle is an entanglement monotone. However, the n-tangle is undefined for odd n>3. Finally we propose a measure related to the n-tangle for mixed state systems of n qubits, and find an analytical formula for this measure for even n.